Currently, functions of a terminal device such as a smartphone or a tablet computer become stronger. A user may use a terminal device such as a smartphone or a tablet computer to watch a video, view a photo, browse a web page, and so on. However, screens of such mobile intelligent terminals are relatively small. In order to obtain better visual experience, generally, display content of these intelligent terminals may be synchronized and output to devices with larger screens, for example, to be synchronized to devices that have larger display screens, such as a projector and a large-screen television. In this way, display content on a small screen of an intelligent terminal may be viewed from a large-screen device. This technology is generally called a screen-sharing technology.
After the screen-sharing technology is used, same content is displayed on two screens; for example, screen sharing is implemented between a smartphone having a touchscreen and a television. When the smartphone is operated in a touch manner, a user performing a touch operation generally can only perform observation by using the touchscreen of the smartphone, and actually cannot experience an effect brought by large-screen display using the screen-sharing technology, which affects user experience.